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首页> 外文期刊>Journal of Applied Polymer Science >ISOTACTIC POLYPROPYLENE/POLYSTYRENE BLENDS - EFFECTS OF THE ADDITION OF A GRAFT COPOLYMER OF PROPYLENE WITH STYRENE
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ISOTACTIC POLYPROPYLENE/POLYSTYRENE BLENDS - EFFECTS OF THE ADDITION OF A GRAFT COPOLYMER OF PROPYLENE WITH STYRENE

机译：等规聚丙烯/苯乙烯共混物-丙烯与苯乙烯接枝共聚物的添加效果

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A novel graft copolymer of unsaturated propylene with styrene (uPP-g-PS) was added to binary blends of isotactic polypropylene (iPP) and atactic polystyrene (aPS) with a view to using such a copolymer as compatibilizer for iPP/aPS materials. Differential scanning calorimetry, optical microscopy, scanning electron microscopy (SEM), wide angle X-ray scattering, and small angle X-ray scattering (SAXS) techniques have been carried out to investigate the phase morphology and structure developed in solution-cast samples of iPP/epsilon PS/uPP-g-PS ternary blends. It was found that the uPP-g-PS addition can provide iPP/aPS-compatibilized materials and that the extent of the achieved compatibilization is composition-dependent. Blends of iPP and aPS exhibited a coarse domain morphology that is characteristic of immiscible polymer systems. By adding 2% (wt/wt) of uPP-g-PS copolymer a very broad particle-size distribution was obtained, even though the particles appeared coated by a smooth interfacial layer, as expected according to a core-shell interfacial model. With increasing uPP-g-PS content (5% wt/wt), a finer dispersion degree of particles, together with morphological evidence of interfacial adhesion, was found. With further increase of uPP-g-PS amount (10% wt/wt) the material showed such a homogeneous texture that neither domains of dispersed phase nor holes could be clearly detected by SEM. The type of interface developed in such iPP/aPS/uPP-g-PS blends was accounted for by an interfacial interpenetration model. The IPP crystalline texture, size, neatness, and regularity of iPP spherulites crystallized from iPP/aPS/uPP-g-PS blends were found to decrease when the copolymer content was slightly increased. Assuming, for the iPP spherulite fibrillae, a two-phase model constituted by alternating parallel crystalline lamellae and amorphous layers, it was shown by SAXS that the phase structure generated in iPP/aPS/uPP-g-PS blends is characterized by crystalline lamellar thickness (L-c) and interlamellar amorphous layer thickness (L-a) higher than that shown by plain iPP; the higher the copolymer content, the higher the L-c and L-a. It should be remarked that considerably larger increases have been found in L-a values. Such SAXS results have been accounted for by assuming that a cocrystallization phenomenon between propylenic sequences of the uPP-g-PS copolymer and iPP occurs and that during such a process PS chains grafted into copolymer sequences remain entrapped in iPP interlamellar amorphous layers, where they form their own separate domains. (C) 1997 John Wiley & Sons, Inc. [References: 19]
机译：将不饱和丙烯与苯乙烯的新型接枝共聚物（uPP-g-PS）添加到全同立构聚丙烯（iPP）和无规立构聚苯乙烯（aPS）的二元共混物中，目的是使用这种共聚物作为iPP / aPS材料的增容剂。已经进行了差示扫描量热法，光学显微镜，扫描电子显微镜（SEM），广角X射线散射和小角X射线散射（SAXS）技术，以研究在溶液浇铸样品中形成的相形态和结构。 iPP /εPS / uPP-g-PS三元混合物。发现添加uPP-g-PS可以提供​​iPP / aPS相容的材料，并且所达到的相容程度取决于组成。 iPP和aPS的共混物表现出粗糙的域形态，这是不混溶的聚合物系统的特征。通过添加2％（wt / wt）的uPP-g-PS共聚物，即使粒子看上去被光滑的界面层覆盖，也获得了非常宽的粒度分布，这是根据核-壳界面模型所预期的。随着uPP-g-PS含量（5％wt / wt）的增加，发现颗粒的分散度更细，并且有界面粘附的形态学证据。随着uPP-g-PS量的进一步增加（10％wt / wt），该材料显示出均匀的质构，以致于分散相域和空穴都无法通过SEM清楚地检测到。在这种iPP / aPS / uPP-g-PS共混物中开发的界面类型由界面互穿模型解释。发现当共聚物含量略微增加时，从iPP / aPS / uPP-g-PS共混物中结晶的iPP球晶的IPP晶体织构，尺寸，净度和规则性降低。假设，对于iPP球晶原纤维，由平行的平行晶体薄片和非晶层交替构成的两相模型，SAXS表明，iPP / aPS / uPP-g-PS共混物中产生的相结构的特征在于晶体层状厚度（Lc）和层间非晶层厚度（La）高于普通iPP所显示的厚度;共聚物含量越高，L-c和L-a越高。应该指出的是，已经发现L-a值有较大的增加。通过假设在uPP-g-PS共聚物的丙炔序列与iPP之间发生共结晶现象，并且在此过程中接枝到共聚物序列中的PS链仍保留在iPP层间无定形层中，从而形成了这样的SAXS结果各自独立的域。 （C）1997 John Wiley＆Sons，Inc. [参考：19]

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